Chainless mercerizer suitable for use with liquid ammonia

ABSTRACT

An improved chainless mercerizer utilizing a series of graduated rollers which increase the efficiency of a chainless mercerizer. Each driven roller is constructed incrementally larger in diameter than the previous driven roller in the direction of fabric travel through the mercerizer. The fabric being mercerized is stretched incrementally tighter as it is transferred from one driven roller to the next succeeding one, thereby increasing the forces opposing widthwise shrinkage. The idler rollers have a uniform diameter approximately that of any of the driven rollers.

United States Patent Calamari, Jr. et al. [451 Apr. 3, 1973 541 CHAINLESS MERCERIZER SUITABLE 3,596,333 8/1971 Tsuruta ..26/l8.6 FOR USE WITH LIQUID AMMONIA 2,239,636 4/1941 Weiss ..68/22 R X Inventors: Timohy A. Calamari J Sidney P. 3,606,772 9/l97l Sando et al. ..68/22 R X h fs gk xi 3:25;; ZS- 53 5; Primary Examiner-William I. Price Assistant Examiner-Philip R. Coc

Att0rneyR. Hoffman and W. Bier [73] Assignee: The United States of America as represented by the Secretary of [57] ABSTRACT Agriculture An improved chainless mercerizer utilizing a series of [22] Flled' May 1971 graduated rollers which increase the efficiency of a [21] Appl. No.: 141,353 chainless mercerizer. Each driven roller is constructed incrementally larger in diameter than the previous 52 US. Cl. ..68/244 26/63 34/71 drive" directim of fabric travel hmugh 63719.], 68/22 the mercerizer. The fabric being mercerized is 5 Int C] 5 3/132 D06f 5 /22, 1306c 15/03 stretched incrementally tighter as it is transferred from [58] Field of Search ..68/22 R, 43, 97, 19.1, 244; one driven roller to the next Succeeding one, thereby 100/161, 162 R, 162 B, 176; 34/95, 71, 116, increasing the forces opposing widthwise shrinkage.

123, 159, l6l;26/l, 63 The idler rollers have a uniform diameter approximately that of any of the driven rollers. [56] References Cited 1 Claim, 3 Drawing Figures UNITED STATES PATENTS 739,580 9/1903 Boral et al. ..68/22 R PATENTEDAPR 3 I975 SHEET 1 UF 2 53R. WILSON AREEVES INVENTORS TIMOI'I-lYACALAMARIQR SIDNEY P SCHREIB ALBERT scoo e ATTORNEY PATENTEUAFR 3 I973 SHEET 2 BF 2 INVENTORS TIMOTHY A.CALAMARI,JR SIDNEY R SCHREIBER ALBERT S. COOPER,JR. WILSON AREEVES ATTORNEY CHAINLESS MERCERIZER SUITABLE FOR USE WITH LIQUID AlVIMONIA A non-exclusive, irrevocable, royalty-free license in the invention herein described, throughout the world for all purposes of the United States Government, with the power to grant sublicenses for such purposes. is hereby granted to the Government of the United States of America.

In copending application Ser. No. 141,360 filed of even date a process is disclosed for the continuous treatment of fabrics with liquid ammonia.

The chainless mercerizer for which the graduated rollers of this invention were developed is comprised of a series of driven rollers of uniform diameter mounted in tandem on some suitable frame. These driven rollers are mounted such that they do not touch, but are close enough to each other to permit the placing of a similar non-driven idler roller in the gap formed above and between each pair of driven rollers. Theseidler rollers are also uniform in diameter, and are either the same or nearly the same diameter as the driven rollers. Fabric to be mercerized is threaded under the bottom of the first driven roller, over the top of the first non-driven roller, under the bottom of the second driven roller, and so on until the fabric is either batched or removed for further finishing. Mercerizing agent is applied to the fabric at some convenient location after the fabric has been completely transferred from the first idler roller. Since the mercerizing agent causes the fabric to shrink, the fabric is pulled tight on the rollers thereby discouraging further shrinkage. One measure of the efficiency of the mercerizer is the amount of fabric shrinkage which occurs. This lateral shrinkage is in turn related to the degree of tightness with which the fabric is stretched over the rollers. The tighter the fabric is stretched, the less the lateral shrinkage. After passing over several driven and non-driven rollers, the mercerizing agent is removed from the fabric using some suitable technique. The fabric is then either drawn off for additional finishing or batched. It is clear, therefore, that the tightness of the fabric on the rollers of the prior art is governedprimarily by the shrinking force of the fabric being mercerized.

It is the object of this invention to incorporate graduated driven rollers of increasing diameter into a device of the prior art such that each driven roller becomes incrementally larger. than the previous one in the direction of fabric travel. The increase in diameter of the rollers will be governed by the type fabric being mercerized, the mercerizing agent, and the operating conditions; however, in no case should the incremental increase in diameter be more than 2 percent between adjacent driven rollers, or more than 5 percent between the smallest and largest driven rollers of the entire series. After removal of the mercerizing agent, the fabric is removed from the machine in a manner identical to that described above for the prior art.

In the accompanying drawing,

FIG. 1 is a plan view of the mercerizer rollers and shows the spacial arrangement of the driven rollers and the associated idler rollers. FIG. 1 also depicts the incremental increase in diameter of the driven rollers in the direction of fabric travel;

FIG. 2 is a side view of the mercerizer showing particularly the driving mechanism for the driven rollers;- and FIG. 3 is a side view of the mercerizer showing the side opposite the drive mechanism, and shows, particularly, the path of the fabric or the yarn through the mercerizer. FIG. 3 also depicts a heat source (two infrared lamps) the purpose of which is to evaporate ammonia from the fabric (as see Example 2, hereinafter).

Referring to FIG. 1, FIG. 2, and FIG. 3 of the drawing, the mercerizier consists of a series of graduated driven rollers 1 through 6 mounted by means of their central shafts 7 in self-centering bearings 8 which are in turn mounted to the bottom of the upper horizontal member of the rigid frame 9 and spaced such that the driven rollers do not touch, but are close enough to each other to permit the placing of similar non-driven idler rollers 10 in the gaps formed above and between each pair of driven rollers. Each driven roller becomes incrementally larger in diameter 7 than the previous driven roller in the direction of fabric travel. The spacing of the driven rollers is further adjusted so that the idler roller shafts 11 just clear the top of the horizontal member of frame 9. The idler rollers 10 are fitted with alignment collars 12 mounted on the idler roller shafts 1 1 such that the collars straddle the vertical component of the upper horizontal member of the rigid frame 9 and thereby maintain proper alignment of the idler rol- Iers during operation. A smaller feed roller 13 is mounted in self-centering bearings 14 which in turn are mounted to the bottom of the upper horizontal member of the frame 9 and spaced such that the feed roller 13 and the drive roller 1 touch and that the line of contact between these rollers forms a squeezing surface.

FIG. 2 shows the drive mechanism which consists of drive sprockets 15 mounted on the driven roller shafts 7. The drive chain 16 runs over the bottom half of each drive sprocket 15. Idler sprockets 17 are mounted on the rigid frame 9 and are spaced such that maximum contact between the chain 16 and the drive sprockets 15 is achieved. The drive train is powered by means of a variable speed motor 18 with speed reducer l9 and controlled by a silicon-controlled rectifier drive 20.

FIG. 3 shows the operation of the mercerizer. Fabric or yarn to be mercerized is batched on the feed assembly 21. The leading edge of the fabric or sheet of yarn is fed through the nip formed between feed roller 13 and driven roller 1 (the smallest of the graduated driven rollers), under roller 1, over the top of the first idler roller 7, under the larger driven roller 2, over the next idler roller and so on until the fabric is either batched or further processed after leaving the last and largest driven roller 6. Liquid ammonia or some other suitable mercerizing agent is applied to the fabric as it passes through treatment tray 22. It is then removed from the fabric or yarns at some convenient location before the fabric passes through the last squeezing surface formed between driven roller 6 and the last idler roller. Speed of travel of the fabric or sheet of yarns through the mercerizer is controlled through the use of the silicon-controlled rectifier drive 20.

EXAMPLE I This example illustrates the continuous tension mercerization of all cotton and blended cotton/polyester sheeting with liquid ammonia using the improved chainless mercerizer. The particular machine employed in this and in the following examples utilized a 2.3 percent overall diameter increase distributed throughout six driven rolls (i.e., the first driven roll measured 4.40 inches in diameter, the sixth and last driven roll measured 4.50 inches in diameter). 1n this example mercerization is terminated by the quenching of the ammonia treated fabric with hot water.

The all-cotton sheeting sample had a thread count of 120x70. The blended sheeting had 5.0 percent cotton and 50 percent polyester in both the warp and filling direction and a thread count of 120X70. Eight inch widths of each fabric were batched on feed rolls. The batched rolls were then placed on a feed assembly which permitted the adjustment of back tension. The fabric was then run through the mercerizer. Liquid ammonia was applied to the fabric by means of a treatment tray located under the second driven roller of the mercerizer. Immersion time was estimated at 0.5 seconds. Mercerization was allowed to proceed for 8 seconds. Hot water was applied to the ammonia treated fabric near the top of the fourth driven roller. This quenching assured an abrupt termination of mercerization. The fabric was stretched progressively as it passed from one graduated driven roller to the next. The dimensions of both the all-cotton and the cotton/polyester blended sheeting both before and after mercerization are given in Table 1 below.

TABLE 1 Dimensions (in.)

Before After Treatment Treatment% Change WarpzFilling Warp:Filling WarpzFillingzArea Cotton Sheeting 52.0 7.9 55.0 7.8 +5.3 -l.3 +4.4 Cotton] Polyester Sheeting 52.0 8.0 54.2 7.9 I +4.2 -l.3 +2.9

As can be seen from this data, filling shrinkage during ammonia mercerization was held to a minimum. Elongation of the warp resulted in an overall increase in fabric area. v I

After removal of the fabrics from the mercerizer, they were crosslinked with a solution containing 1 percent dimethylol-methoxyethyl carbamate and 0.8% Zn(NO O using a pad, dry, cure procedure. The physical properties of the all-cotton samples before and after crosslinking are compared in Table 11 below as are those for the blended cotton/polyester samples in Table 111.

1/ Removed by water quenching TABLE Ill Tearing Stoll Flex Strength Abrasion Wrinkle Recovery Filling Cycles Angle (W+F) (gms.) (warp) (Conditioned) (Wet) Control 120x70 Blended Sheeting) 1733 3814 260 267 Crosslinked Control 733 2076 281 277 Liquid NH; for 8 sec. 1/ 1913 3058 248 273 Liquid NH, for 8 sec. then Crosslinked 1/ 827 2098 290 281 1/ Removed by water quenching As can be seen from the data given above in Tables 1 and 3, ammonia mercerization causes significant improvement in the physical properties of the treated cotton and cotton/polyester sheeting both before and after crosslinking treatments.

EXAMPLE 2 This example is identical to Example 1 except that the ammonia was removed from the fabric through evaporation induced by means of two 150 watt infrared lamps as a heat source. Evaporation was begun 3 seconds after the fabric was immersed in the liquid ammonia, and was over percent complete 10 seconds later. Some physical properties of the all-cotton and blended samples before and after mercerfzation and crosslinking are compared below in Tables 1V and V.

TABLE [V Tearing Stoll Flex Strength Abrasion Wrinkle Recovery Filling Cycles Angle (W+F) (gms.) (Warp) (Conditioned) (Wet) Control l 20X70 Cotton Sheeting 907 1016 209 176 Crosslinked Control 327 159 271 259 Liquid NH; for 8 sec. 1/ 960 1796 219 210 Liquid NH; for 8 see. then Crosslinked 1/ 527 330 282 252 1/ Removed by a heat induced Evaporation TABLE V Tearing Stoll Flex Strength Abrasion Wrinkle Recovery Filling Cycles Angle (W-i-F) (gms.) (Warp) (Conditioned) (Wet) Control x70 Blended Sheeting) 1733 3814 260 267 Crosslinked Control 7 33 2096 281 272 Liquid NH, for 8 sec. 1/ 1783 5196 272 280 Liquid NH; for 8 sec. then crosslinked 1! 947 4373 294 284 1/ Removed by heat induced evaporation EXAM PLE 3 The example illustrates the continuous tension mercerization of cotton yarn with liquid ammonia. The yarn used in this work was a loose twist greige 10/2 Deltapine cotton yarn having a T.M. of 2.21 (6.99 tpi) in the singles with a reverse ply T.M. of 3.11 (6.95 tpi). A sheet of three ends was batched on a skein winder cerized yarn are given below in Table VI.

TABLE VI Breaking Elongation Strength Tenacity To Break (a) (q/ x) Control (10.2 yarn) 1274 10.8 7.7 Liquid NI I for 5 see. 1524 12.6 8.2

As can be seen from the data given above, substantial increases in yarn breaking strength and tenacity can be obtained without a correspondingly large decrease in elongation. Yarn length was increased 18.6 percent by the treatment.

EXAMPLE 4 This example illustrates the continuous tension mercerization of a sample of cotton tubular knit fabric with liquid ammonia. The fabric used was a plain jersey knit from a greige 40/2 balanced yarn. It had 41 courses and 34 wales/in. and weighed 3.0 oz./yd The flattened width of the tube was about 5 inches. A floating spreader bar was placed inside the tube so that it spread the knit jersey immediately before entering the nip formed between the first driven roller and the feed roller. The tube was then threaded through the machine in a manner similar to that outlined in'Example l. Ammonia was applied as indicated in Example 1 and removed using infrared lamps as in Examples 2 and 3. Over 90 percent of the ammonia was removed 12 seconds after the initial immersion. After mercerizamethoxyethyl carbamate for enhanced dimensional stability to washing. The data gathered on these samples is given below in Table VII.

TABLE VIII Crosslinked Control 44 Liquid NIL, for 12 sec." 86 Liquid NH for 12 sec."

then crosslinked 64 ll Crosslinked with 10% dimethylolmethoxyethyl carbamate using a pad, dry, and cure procedure. 2/ Removed using heat induced evaporation.

As the data show the bursting strength of ammonia mercerized, then crosslinked jersey is greatly improved over that of a non-pretreated crosslinked control.

We claim:

1. In a chainless mercerizing machine comprising a first roll series consisting of a plurality of smooth surfaced, horizontally disposed, axially parallel, tandem and rotatably mounted rolls, radially spaced to provide nip space and rotational clearancebetween ad'acent r0 ls, said first roll series being provided with a rivmg means adapted to revolve the rolls severally at constant and equal rate; a second roll series less by one in number and similar to said first roll series, said second roll series consisting of a plurality of uniform, smooth surfaced, radially spaced, horizontally disposed, axially parallel rolls, tandem mounted and freely rotatable, said second roll series being positioned immediately above said first roll series, each individual roll member of said second roll series being positioned within the nip space formed by a pair of rolls of said first roll series immediately beneath, and being driven by both'members of said pair via roll surface contact; the improvement which consists of an incremental increase 'in' roll diameter from the first driven roll relative to fabric travel to the last driven roll, the diametric increase being at least 1 percent and not more than 5 percent distributed throughout all of the driven rolls. 

1. In a chainless mercerizing machine comprising a first roll series consisting of a plurality of smooth surfaced, horizontally disposed, axially parallel, tandem and rotatably mounted rolls, radially spaced to provide nip space and rotational clearance between adjacent rolls, said first roll series being provided with a driving means adapted to revolve the rolls severally at constant and equal rate; a second roll series less by one in number and similar to said first roll series, said second roll series consisting of a plurality of uniform, smooth surfaced, radially spaced, horizontally disposed, axially parallel rolls, tandem mounted and freely rotatable, said second roll series being positioned immediately above said first roll series, each individual roll member of said second roll series being positioned within the nip space formed by a pair of rolls of said first roll series immediately beneath, and being driven by both members of said pair via roll surface contact; the improvement which consists of an incremental increase in roll diameter from the first driven roll relative to fabric travel to the last driven roll, the diametric increase being at least 1 percent and not more than 5 percent distributed throughout all of the driven rolls. 